So i'm having issues PXE booting across subnets in the school district we just laid sccm 2012 sp1 down on. A few notes about our environment:

Each AD Site has its own local dhcp/dns There's 1 SCCM server/distribution point in our environment, it's at our HighSchool DHCP and SCCM Servers are on separate servers, not combined At the HighSchool, pxe booting works perfectly At each of the outside campuses, boundaries are all setup correctly/etc and clients are installing fine, so I know as far as administration/site boundaries are concerned it should be setup correctly. At my external campus/subnet, I have the following DHCP options setup in their local dhcp server: Option 066 : Boot Server Host Name = value "mps-sccm" , which is our sccm server Option 067 Bootfile Name = smsboot\x86\pxeboot.com (is this right? i'm iffy about this one...at our high school where pxe is working perfectly the PXE screen first grabs an ip successfully, then gets WDSNBP from our sccm server. Here's a screenshot:

Ok, so we try to PXE boot from another campus/subnet, and we get the following screen (notice a lot of text is missing from the success screen from the High School...I don't know if that's relevant?), then the following error message: Pre-Boot screen: Quickly followed by this error:

I'm not sure what to do from here, but I need to be able to PXE boot back to our main SCCM server from the external subnets/sites. I've read online about having to use IP Helpers/etc, but then I've read where some did not have to use them that were using DHCP options. I'm open to ANY suggestions.

Well, I fixed this about 10 minutes after posting. I changed from SMSboot\x86\pxeboot.com to SMSboot\x64\wdsnbp.com and it worked like a charm. I know without a doubt last week I tried this combination and it did not work. I am also pretty sure that this problem was also being caused by using E3100 network adapters instead of VMWNet3 adapters for the VMware SCCM virtual server, which I posted here: